Early days of flying. All replicas down to the spinning engine of the legendary Sopwith Camel. Whilst they were noisy with unmuffled engines, nowhere near the deafening roar of an F-22 or F-35 with full power. Stealthy in radar signature, but not noise. Some may have pieces of the original aircraft, but essentially remanufactured from the original plans. Hard to believe these primitive aircraft were the precursor to modern military jets, but these were at the height of technology 100 years ago